Oligomerization and Aggregation of Bovine Pancreatic Ribonuclease A:Backbone Hydration Probed by Infrared Band-Shift

Abstract

Protein hydration plays a crucial role in almost all aspects of biomolecular processes. In this research, we studied the hydration/dehydration-induced infrared amide I band-shift by using poly-L-lysine and bovine pancreas ribonuclease A as model polypeptides. It was found that a 1-4 cm(-1) shift could be clearly distinguished for all regular secondary structures during protein thermal unfolding. This shift was proven to be due to backbone hydration but not from experimental error, temperature effect or possible incomplete hydrogen/deuterium exchange of the samples. Moreover, we also found that protein aggregation was closely associated with the backbone hydration/dehydration status of proteins. In conditions favoring aggregation, a significant shift to a higher wavenumber of the band from the intermolecular beta-sheet structures in aggregates was observed. The present study suggested that the changes of the amounts of regular secondary structures could be monitored by the intensity changes, while the changes of the hydration status could be monitored by the shift of the infrared bands.

A Desolvation Model for Trifluoroethanol-Induced Aggregation of Enhanced Green Fluorescent Protein

“…Decreases in the free energy of the bulk solvent are expected to favor the formation of solvent-shielded and oligomeric structures (40). In addition, desolvation is consistent with previous reports that hydration impedes amyloid aggregation (41)(42)(43)(44). Therefore, we believe that the simplicity of our model, combined with the fact that it offers a straightforward explanation for both the structural changes and the aggregation enhancement observed for proteins in TFE, make it a reasonable initial analysis.…”

Interplay between desolvation and secondary structure in mediating cosolvent and temperature induced alpha-synuclein aggregation

“…Zhang and Yan demonstrated aggregation coupled to dehydration for proteins in the presence of ethanol, and they suggested that similar effects should occur in TFE [25]. In addition, aggregation enhancement was observed when reverse micelles were used to limit water availability [26].…”

Two-dimensional correlation spectroscopy — Biannual survey 2007–2009

“…Spectra were normalized with concentration by Czarnecki and Wojtków [57] prior to 2D analysis. Lai et al [58] used the baseline correction, while Zhang and Yan [59] applied non-normalized Fourier self deconvolution before 2D analysis. Kamerzell et al [60] used several pretreatment steps, including the ATR effect correction, subtraction of water contribution, and normalization of concentration effect.…”

“…Zhang and Yan [59] reported the 2D IR study of the H/D exchange reaction of bovine pancreas ribonuclease A. Distinction between deuterated and nondeuterated polypeptide chains was possible.…”

“…Zhang et al [59] used 2D IR for the H/D exchange of bovine pancreas ribonuclease A. Wang et al [85,189] studied thermally induced and pressure induced unfolding of ribonuclease A. Sánchez et al [188] reported the 2D IR study of thermal unfolding of bovine serum albumin interacting with dirhamnolipid biosurfactant secreted by P. aeruginosa. Yu et al [231] used 2D NIR to study the pH-induced secondary structure change and binding interaction between bovine serum albumin and famotidine, a histamine H 2 -receptor antagonist.…”